On Wed, Feb 20, 2019 at 02:37:21PM -0500, Doug Ledford wrote: >> No, that would break the API users have today. > That's a given. You can't implement a new feature like namespaces while > preserving non-namespace behavior Sure I can, that is why we have this mode flag. In the compat mode there is no user visible behavior change and you don't get namespaces. In new-mode there are user visible changes. Admin chooses which mode they want. > gap. I say this because I don't know of any real world use involving > RDMA, containers, non-init_net namespaces, and RDMA access. Do you? Yes, sites are mixing RDMA and net namespace'd containers. They need things to not change while they review their orchestration/etc. This is the whole philosophy for Linux, don't break the userspace. Parav's solution is really ugly, but does get the job done. This is doubly true when we expect to have entire classes of HW that can't support a 'child' ib_device. Those would be permanently broken with net namespaces if we don't have a compat. Jason
